The
division of the Mongol Empire began when
Möngke Khan died in 1259 with no declared successor, precipitating infighting between members of the
Tolui family line for the title of
Great Khan that escalated to the
Toluid Civil War. This civil war, along with the
Berke–Hulagu war and the subsequent
Kaidu–Kublai war greatly weakened the authority of the Great Khan over the entirety of the
Mongol Empire and the empire fractured into autonomous khanates, including the
Golden Horde in the northwest, the
Chagatai Khanate in the middle, the
Ilkhanate in the southwest, and the
Yuan dynasty in the east based in modern-day
Beijing, although the Yuan emperors held the nominal title of
Khagan of the empire. The four khanates each pursued their own separate interests and objectives, and fell at different times.